Salvo ammunition for multiple bore open chamber gun

ABSTRACT

Multiple projectile salvo ammunition for a salvo-firing open chamber gun having multiple bores. The ammunition is characterized by multiple mutually axially coextensive projectiles arranged in a fixed array about the longitudinal axis of the ammunition round in a manner such that projectiles are coaxially aligned in one-to-one relation with the gun bores when the round is positioned in firing position.

United States Patent 1191 1111 3,855,931

Dardick Dec. 24, 1974 [5 SALVO AMMUNITION FOR MULTIPLE 3,129,664 4/1964 Reed 102/38 O O CHAMBER G 3,146,673 9/1964 Reed 102/38 X 3,437,039 4/1969 Hawthorne 102/38 [75] Inventor: Davrd Dardick, Palos Verdes Peninsula, Calif. Primary ExaminerRobert F. Stahl [73] Assrgnee. TRW lnc., Redondo Beach, Calrf. Attorney, Agent or Firm Daniel T Anderson; [22] Filed: Dec. 30, 1968 Donald R. Nyhagen; Jerry A. Dinardo [21] Appl. No.: 787,754

Related US. Application Data [57] ABSTRACT [62] Division of S61. No. 665,139, Sept. 1, 19 7', Pat. N0.

3150 Multiple projectile salvo ammunition for a salvo-firing I open chamber gun having multiple bores. The ammu- [52] U.S. Cl 102/38, 102/43 P Men is Characterized by multiple mutually axially [51] Int. Cl. F42b 5/02, F42b 9/06 extensive projectiles arranged in a fixed array about [58] Fleld of Search 102/38 43 the longitudinal axis of the ammunition round in a 102/44; 89/35 155 manner such that projectiles are coaxially aligned in one-to-one relation with the gun bores when the round [56] References C'ted is positioned in firing position.

UNITED STATES PATENTS 2,865,126 12/1958 Dardick 102/38 X 5 Claims, 8 Drawing Figures SALVO AMMUNITION FOR MULTIPLE BORE OPEN CHAMBER GUN This application is a division of my copending application Ser. No. 665,139, filed Sept. 1, 1967, and entitled Salvo Firing Open Chamber Gun, now issued U.S. Pat. No. 3,501,998.

REFERENCE TO COPENDING APPLICATIONS Reference is made herein to copending applications Ser. No. 665,136, filed Sept. 1, 1967, entitled Semi- Combustible Ammunition for Open Chamber Breech Mechanism, now issued U.S. Pat. No. 3,507,219 and Ser. No. 671,910, filed Sept. 1, 1967, entitled Sealed Open Chamber Breech Mechanism and Caseless Ammunition Therefor now issued U.S. Pat. No. 3,446,113.

BACKGROUND OF THE INVENTION nism including a breech frame having a chamber containing a rotary carrier or cylinder with one or more firing chambers which open laterally through the circumference of the cylinder. The cylinder is supported on the breech frame for rotation or oscillation on an axis parallel to and spaced from the gun barrel to locate each firing chamber in an ammunition infeed position, wherein the open side of the chamber registers with an ammunition infeed opening in the breech frame to permit lateral infeed movement of an ammunition round into the chamber, and a firing position wherein the breech frame firing strap closes the open side of the firing chamber and the firing chamber opens forwardly to the gun bore to condition the gun for firing of the round in the chamber. Each firing chamber rotates from firing position to infeed position through an intervening cartridge case ejection position wherein the open side of the chamber registers with a cartridge case ejection opening in the breech frame to permit lateral ejection of the spent cartridge case after firing.

The open chamber guns disclosed in the prior art patents listed above are designed to fire ammunition rounds containing a single projectile. To this end, the guns are characterized by a single barrel at each firing station which is disposed for coaxial alignment with each firing chamber upon rotation of the respective chamber to firing position at the station.

My copending application, Ser. No. 665,139, discloses a salvo-firing open chamber gun equipped with a number of bores at each firing station which open rearwardly to a common firing chamber in firing position. Each time the gun is fired, projectiles are propelled simultaneously through the several gun bores at the firing station to produce a salvo.

SUMMARY OF THE INVENTION The present invention provides salvo ammunition for a salvo-firing open chamber gun such as that disclosed in copending application Ser. No. 665,139. This ammunition is characterized by a generally triangular round shape in transverse cross-section which compliments the generally triangular round firing chamber or firing chambers of the gun. Each ammunition round contains a number of mutually axially coextensive projectiles arranges in a fixed array about the longitudinal axis of the round. The number of projectiles in each round equals the number of bores at each firing station of the gun. The fixed projectile array conforms to the array of the gun bores at each firing station.

When an ammunition round is situated in firing position at the station, the mating triangular round shapes of the ammunition round and its containing firing chamber orient the ammunition round in a fixed angular position about the axis of the chamber wherein the projectiles of the round register in one-to-one firing relation with the gun bores. Accordingly, when the round is fired, its several projectiles are propelled in unison through the bores, whereby the gun fires salvos rather than single projectiles.

According to the preferred practice of the invention, each ammunition round contains three projectiles. These projectiles are equally radially spaced from the longitudinal axis of the round and are located in radial planes, respectively, which contain the longitudinal axis of the round and bisect it three interior angles. This particular projectile array achieves two important advantages. First, it results in optimum chamberage, that is optimum propellant volume for given projectile and gun bore diameter. Secondly, the projectile array provides each ammunition round with minimum transverse cross-section for given projectile and gun bore diameter. It will be understood, of course, that the multiple gun bores at each firing station will be arranged in the same array as the projectiles so that the projectiles of a round in firing position will register in one-to-one relation with the bores.

In accordance with the teachings in the open chamber gun patents mentioned earlier, the firing chamber or firing chambers of an open chamber gun may have either a generally isosceles triangular round crosssection or a generally equilateral triangular round cross-section, the present ammunition may conform to either of these firing chamber cross-section A present isosceles triangular round may occupy only one angular position in a firing chamber, wherein its curved hose side is exposed at the open side of the chamber. A present equilateral triangular round, on the other, may be oriented in any one of three angular positions in a firing chamber, wherein any one of the three sides of the round is exposed at the open side of the chamber. The present ammunition may embody either a caseless or cased construction similar to the ammunition disclosed in the earlier mentioned copending application.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.'1 is a side-elevation of a salvo-firing open chamber gun according to application Ser. No. 665,139;

FIG. 2, is an enlarged fragmentary longitudinal section through the gun;

FIG. 3 is a section taken on line 33 in FIG. 2;

FIG. 4 is an enlarged section taken on line 4-4 in FIG. 1',

FIG. 5 is a section taken on line 5-5 in FIG. 2;

FIG. 6 is a perspective view of a salvo ammunition round accoring to the present invention which is adapted to be fired in the open chamber gun of FIGS. 1 through 5;

FIG. 7 is a longitudinal section through the round; and

FIG. 8 is an enlarged section taken on line 88 in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference is made first to FIGS. 6 through 8 illustrating a salvo-type, multiple projectile open chamber ammunition round 10, according to the invention. The illustrated ammunition is cased ammunition and comprises an outer yieldable, non-combustible cartridge case 12 which is typically constructed of a suitable noncombustible plastic, such as one of the plastic materials referred to in the earlier mentioned patents. Cartridge case 12 has the preferred, generally triangular round shape in transverse cross-section which characterizes open chamber ammunition and includes front and rear transverse end walls 14 and 16, respectively, and longitudinal side walls 18. Contained within the cartridge case 12 are a plurality of projectiles 20 and a propellant charge 22.

The projectiles 20 are elongated longitudinally of the round, and, in this instance, have conventional bullet shapes. In the particular salvo ammunition illustrated, the projectiles are three in number and are uniformly spaced about the longitudinal axis of the round in such a way that the projectiles are disposed in radial planes, respectively, containing the axis and the three longitudinal apex edges of the cartridge case 12. Extending through the front end wall 14 of the cartridge case, in coaxial alignment with the projectiles, are bores 24. Sealed to the walls of these bores are obturating sleeves 26 frictio'nally receiving the projectiles. The propellant charge 22 fills the remaining interior volume of the cartridge case 12 in such manner that the propellant encapsulates the projectiles and their obturating sleeves. Mounted in the rear end wall 16 of the cartridge case 12 is a primer 28.

Turning now to FIGS. 1 through 5, there is illustrated a salvo-firing open chamber gun 30 like that disclosed in application Ser. No. 665,139 in which the salvo round is adapted to be fired. The gun has an open chamber breech mechanism 31, including a breech frame 32 having the usual flat rectangular shape and containing a chamber 34. Chamber 34 opens laterally through opposite sides of the breech frame 32 to form ammunition infeed and cartridge case ejection openings to the chamber.

Rotatably supported on the breech frame 32 within the chamber 34, for turning on an axis 36, is an open chamber carrier or cylinder 38. This cylinder contains at least one (and in this instance three) firing chambers 40 which open laterally through the circumference of the cylinder and longitudinally through the ends of the cylinder. Cylinder 38 is rotatable in the chamber 34 to locate each firing chamber 40 in an ammunition infeed position, a firing position, and a cartridge case ejection position. The open side of each firing chamber, when in infeed position, registers with the ammunition infeed opening in the breech frame to permit lateral infeed movement of a present salvo round 10 into the firing chamber. When in firing position, the open side of each firing chamber is closed by the firing strap 42 of the breech frame 32 to permit firing of the round in the chamber. When a firing chamber occupies its ejection position, the open side of the chamber registers with the breech frame ejection opening to permit lateral ejection of spent cartridge case 12 of the round 10 from the chamber after firing. Extending coaxially from the rear end of the cylinder 38, and rotatably through the rear end of the breech frame 32, is a shaft 44 by which the cylinder may be driven to infeed, firing and ejection positions. In this regard, attention is directed to the fact that the cylinder may be driven in undirectional rotation or oscillation through infeed, firing, and ejection positions. A conventional firing means or pin 46 is provided for firing a round 10 in a firing chamber 40 when the latter occupies firing position.

The gun is equipped with a number of bores 48 equal to the number of projectiles 20 in a salvo round 10. In this instance, the bores are defined by a cluster 50 of separate barrels 52 which are secured to an extend forwardly from the front end of the breech frame 32, in line with the firing station of the breech mechanism 31. The barrels are disposed in spaced, generally parallel relation to the rotation axis 36 of the breech cylinder 38 in such a way that the projectiles 20 of a present ammunition round 10, when contained within a cylinder firing chamber 40 with the latter in firing position, are coaxially aligned with the bores 48, respectively. Accordingly, when the round is fired, the projectiles are propelled by propellant gas pressure, forwardly in unison through their respective barrels. The present breech mechanism, therefore, is effective to fire a group or cluster of projectiles.

The open chamber gun 30 is equipped with adjusting means 54 for relatively angularly displacing the barrels 52 in such a way to vary the dispersion pattern of the fired projectiles 20 in flight. To this end, the barrels of the illustrated gun are designed to have limited lateral flexibility and the adjusting means 54 is adjustable to effect lateral bending or deflection of the front ends of the barrels toward and away from oneanother. The particular adjusting means illustrated comprises a collar 56 threaded on the forward end of a barrel sleeve or shroud 58 which is secured at its rear end to and extends forwardly from the front end of the breech frame 32 in surrounding relation to the barrels 52. The rear ends of the barrels extend through and are secured to a cylindrical plug 59 which is fixed within the rear end of the barrel sleeve. The internal diameter of the sleeve 58 issufficiently large to provide clearance between the sleeve and the barrels, and the barrels are stressed to normally diverge toward their forward ends. Secured to and extending radially from the front ends of the barrels and through longitudinal clearance slots 60 in the front end of sleeve 58 are tapered cams 62. The barrel adjusting collar 56 has an internal conical camming surface 64 engaging the barrel cams 62 in such a manner that forward axial adjustment of the collar relative to the barrel sleeve 58, i.e., axial adjustment of the collar away from the breech frame 32, earns the forward ends of the barrels 52 inwardly toward one another to reduce the relative angular divergence of the barrels. Rearward adjustment of the collar permits the barrels to spring outwardly away from one another and thereby increase the relative angular divergence of the barrels. It will now be understood, therefore, that forward axial adjustment of the collar 56 reduces the dispersion of the projectiles 20 which are discharged through the barrels 52 during firing of each salvo round 10 in the tiles 20 which are uniformly spaced about the longitudinal axis of the round and located in radial planes containing the axis and the three longitudinal apex edges, respectively, of the round. Accordingly, the projectiles are effectively arranged in a triangular pattern. The

barrels S2 of the gun 30 are arranged in the same triangular pattern and are uniformly spaced about an axis which concides with the longitudinal axis of each cylinder firing chamber 40 when the latter occupies its firing position. The barrels are thus located in three uniformly spaced radial planes containing the firing chamber axis and the longitudinal axes of the respective barrels. Axial adjustment of the collar 56 is thus effective to relatively displace the barrels toward and away from one another in their respective radial planes.

The illustrated equilateral triangular round shape of the ammunition rounds l0 and cylinder firing chambers 40 has a unique advantage in the present open chamber gun 30. Thus, this particular shape permits each round to be positioned in a firing chamber with any one of the side walls 18 of its cartridge case 12 exposed at the open side of the chamber. ln this regard, it will be evident that because of the illustrated arrangement of the projectiles 20 in each round, the projectiles 20 in the round are automatically coaxially aligned with the bores 48 in each of the three positions which the round may occupy in the firing chamber. As is conventional in open chamber ammunition of this type, the sidewalls 18 of the cartridge case 12 of each ammunition round are cylindrically curved to the same ra dius as the breech cylinder 38 so that when the round is positioned in a cylinder firing chamber 40, the exposed side of the round is flush with the circumference of the cylinder. As noted earlier, the cartridge case of each round is constructed of a yieldable, noncombustible material, such as a plastic material, which expands outwardly against the walls of the firing chamber and the confronting surface of the breech frame firing strap 42 during firing of the round to seal the breech interfaces against propellant gas leakage.

lt will be immediately evident to those skilled in the art that while the illustrated ammunition round 10 of the invention contains three projectiles, each round may contain a lesser number or a greater number of projectiles. The number of barrels 52 in the gun, of

course, will be reduced or increased accordingly and will be arranged to coincide with the projectiles of each round when in firing position. Obviously, other means that the illustrated collar 56 may be employed for is adjusting the relative divergence of the barrels. For example, the barrel adjusting means may comprise a conical tapered wedge supported for axial adjustment between the barrels in such away as to cam the barrels radially outward away from one another. In this case, the barrels will be stressed to normally spring inwardly toward chamber registers with the breech frame infeed opening to permit lateral infeed movement of an ammunition round 10 into the chamber. The cylinder is then rotated to locate the firing chamber in firing position and the firing means 46 are actuated to fire the round. The several projectiles 20 of the round are propelled forwardly in unison, by propellant gas pressure, through the barrels 52. The dispersion of the projectiles in flight is determined by the relative divergence of the barrels. This divergence, and hence the dispersion pattern of the projectiles, are varied by axial adjustment of the barrel adjusting collar 56.

After firing, the cylinder 38 is rotated to locate the firing chamber in case ejection position to effect lateral ejection of the spent cartridge case 12 of the fired round from the chamber.

As noted earlier, while the invention is disclosed in connection with an open chamber gun having fixed barrels carried by the breech frame, the salvo ammunition of the invention may be fired in a rotary barrel open chamber gun of the type illustrated in the earlier mentioned US. Pat. No. 3,041,939. In this latter case, the barrel cluster or clusters of the present gun will be carried by and rotate with the breech cylinder in the same way as do the single barrels in the patent. Moreover, the present salvo ammunition invention may be embodied in semicombustible and caseless open chamber ammunition of the kind disclosed in the earlier mentioned copending applications.

At this point, attention is directed to the fact that the three projectiles 20 of the ammunition round 10 are uniformly spaced from the longitudinal axis of the round, and the longitudinal axes of the projectiles are disposed in planes which bisect the interior angles of the round. This arrangement places the projectiles within the three interior corners or apices of the round and provides two important advantages. First, it results in optimum chamberage, that is optimum propellant volume for a given projectile diameter and hence gun bore diameter. Secondly, the illustrated projectile placement provides the ammunition with a minimum transverse cross-section for a given projectile diameter and gun bore diameter.

What is claimed as new in support of letters patent is:

l. Salvo-type ammunition to be fired in a multiple bore open chamber gun of the character described,

comprising:

an ammunition round of generally triangular round shape in transverse cross-section having a central longitudinal axis and containing a rear propellant charge and a plurality of forward positionally fixed mutually axially coextensive elongate projectiles having individual longitudinal axes substantially parallel to and uniformly spaced from said cent'ral axis of said round, and said projectiles being angularly spaced in a predetermined array about said central axis.

2. Ammunition according to claim 1, wherein:

said round contains three projectiles which have their individual longitudinal axes disposed in planes bisecting the interior angles of the round.

3. Ammunition according to claim 1, wherein:

said round has a generally equilateral triangular round shape in transverse cross-section; and

projectiles, respectively; and

obturator sleeves sealed to the walls of said latter bores and receiving said projectiles, respectively.

5. Ammunition according to claim 3, wherein:

said projectiles are three in number; and

said projectiles have their longitudinal axes located in planes, respectively, bisecting the three interior angles of the round. 

1. Salvo-type ammunition to be fired in a multiple bore open chamber gun of the character described, comprising: an ammunition round of generally triangular round shape in transverse cross-section having a central longitudinal axis and containing a rear propellant charge and a plurality of forward positionally fixed mutually axially coextensive elongate projectiles having individual longitudinal axes substantially parallel to and uniformly spaced from said central axis of said round, and said projectiles being angularly spaced in a predetermined array about said central axis.
 2. Ammunition according to claim 1, wherein: said round contains three projectiles which have their individual longitudinal axes disposed in planes bisecting the interior angles of the round.
 3. Ammunition according to claim 1, wherein: said round has a generally equilateral triangular round shape in transverse cross-section; and said projectiles are uniformly angularly spaced in a predetermined symetrical array about said central axis.
 4. Ammunition according to claim 1, wherein: said ammunition round is an open chamber ammunition round including an outer yieldable non-combustible cartridge case of generally triangular round shape in transverse cross-section and having a front end wall; said wall contains bores coaxially aligned with said projectiles, respectively; and obturator sleeves sealed to the walls of said latter bores and receiving said projectiles, respectively.
 5. Ammunition according to claim 3, wherein: said projectiles are three in number; and said projectiles have their longitudinal axes located in planes, respectively, bisecting the three interior angles of the round. 